style.css

body {
    font-size: 20px;
    align-items: center;
    align-content: center;
    margin: 0 auto;
    background-color: rgb(120, 255, 181);
}
.container{
    height:90%;
    width:40%;
    margin: 1% auto; 
   
  
}
input {
    line-height:30px;
}
#add-btn {
    line-height:30px;
    font-size: 15px;
    background-color:#4426af;
    color: white;
}
.msg {
    margin: 30px auto; 
    padding: 10px; 
    border-radius: 5px; 
    color: #24052c; 
    background: #dff0d8; 
    border: 1px solid #3c763d;
    width: 30%;
    text-align: center;
}
table{
    width: 50%;
    margin: 30px 1px;
    border-collapse: collapse;
    text-align: left;
}
tr {
    border-bottom: 1px solid #cbcbcb;
}
th, td{
    border: none;
    height: 30px;
    padding: 2px;
}
tr:hover {
    background: #F5F5F5;
}
.del_btn {
    text-decoration: none;
    padding: 2px 5px;
    color: white;
    border-radius: 3px;
    background: #800000;
}